The invention relates to a door for closing a chamber opening in a chamber wall of a vacuum chamber in relation to a surrounding space, in which the vacuum chamber is located, comprising a door housing arranged in the surrounding space, a closure member which is arranged in the surrounding space and is adjustable over an adjustment path from an open position for opening up the chamber opening into a closed position for closing the chamber opening, and a rod which has a longitudinal axis and to which the closure member is connected, wherein the closure member is adjusted over the adjustment path by a first movement of the rod and a subsequent second movement of the rod, and the first movement of the rod, by which the closure member is adjusted from the open position into an intermediate position, is a displacement of the rod in the direction of its longitudinal axis, and the subsequent second movement of the rod, by which the closure member is adjusted from the intermediate position into the closed position, is a displacement of the rod in a direction at an angle to its longitudinal axis and/or a pivoting of the rod about a pivot axis which is at a right angle to its longitudinal axis.
Doors of vacuum chambers serve, in the closed state of the door, to seal a chamber opening in the chamber wall of a vacuum chamber in relation to the surrounding atmosphere in order to maintain a vacuum in the vacuum chamber. In the open state of the door, it is possible, for example, for substrates to be processed to be introduced into the vacuum chamber through the opening.
In the case of important regions of use, in which processes are carried out under vacuum conditions, for example in semiconductor technology or coating technology, for example for producing screens, clean room conditions have to prevail in the space surrounding the vacuum chamber. The substrates to be processed are thereby protected against accumulations of harmful dirt particles.
Particles which are formed during the operation of the door and are released into the surroundings may be a problem here. Of a particularly critical nature is the release of particles here specifically in the region through which the substrates are introduced into the vacuum chamber.
Vacuum doors of the type mentioned at the beginning with a substantially L-shaped adjustment path of the closure member during the closing of the door are known from DE 19 633 798 A1, WO 2011/091455 A1 and U.S. Pat. No. 7,611,122 B2. The closing of the door from its open position takes place here by the fact that the rod to which the closure member is attached is initially displaced axially (=first movement of the rod) and, as a result, pivoting of the rod about a pivot axis which is at right angles to its longitudinal axis takes place (=second movement of the rod). For the first movement of the rod, the latter is mounted displaceably in relation to a basic body of the door. For the second movement of the rod, the basic body is pivotable about the pivot axis in relation to the chamber wall of the vacuum chamber. For pivoting the basic body about the longitudinal axis, piston-cylinder units are provided in the document mentioned first, the pistons of which are supported on the chamber wall on both sides of the pivot axis. In the document mentioned second, tubular, inflatable elements are arranged as actuators on both sides of the pivot axis. Simply designed and cost-effective doors can be provided in this manner; however, a large amount of particles are generated during the operation.
U.S. Pat. No. 6,056,266 discloses a door in which the door housing is attached rigidly to the chamber wall. A rod is displaceable axially by a piston-cylinder unit. A support unit which forms a cylinder space of a transverse piston-cylinder unit is attached to the rod. The closure member is attached to the piston rod of said transverse piston-cylinder unit. Overall, an L-shaped movement of the closure member is therefore again carried out. By actuation of the piston-cylinder units, of which the transverse piston-cylinder units also lie directly in front of the chamber opening, a high particle loading also occurs in the case of this door. A similar door is also known from U.S. Pat. No. 6,899,316 B2.
A door in which a reduced particle loading for substrates introduced through the chamber opening of a sluice chamber is intended to be achieved is revealed in U.S. Pat. No. 6,916,009 B2. The closure member is moved from its open position via an L-shaped adjustment path into its closed position in which it seals the opening in the chamber wall. To adjust the closure member from its open position into an intermediate position, first and second longitudinal piston-cylinder units are provided which are each attached to a housing part and displace rods to which the closure member is connected. In order to adjust the closure member from its intermediate position into the closed position, the housing parts are adjusted in relation to the chamber wall of the sluice chamber by transverse piston-cylinder units. The closure member is connected to the rods via connecting pieces which are at right angles to the rods and protrude through elongated holes in a cover plate. A filtered airflow is guided past the cover plate. Although an improvement in the particle loading in comparison to previously known designs of doors is achieved by this design, this particle loading may still be too high for sensitive uses.
L-shaped movements of closure members are known in different ways in the case of valves which serve for providing a seal between two vacuum chambers or a vacuum chamber and a pipe. The closure members are in each case arranged here in the interior of a valve housing and, in their closed position, seal a valve opening of the valve housing. The interior space of the valve housing in which the closure member is arranged constitutes a vacuum region here and, in the open state of the vacuum valve, forms a passageway through the vacuum valve. Examples of L valves, in which, during the closing of the vacuum valve, first of all an axial displacement of the valve rod takes place and, as a consequence, a displacement which is at right angles thereto takes place, are found in US 2014/0131603 A1 and US 2011/0175011 A1. Vacuum valves with at least substantially L-shaped movements of the closure member, in which, subsequent to an axial displacement of the valve rod, tilting of the valve rod about an axis which is at right angles to the longitudinal axis of the valve rod takes place, are revealed, for example, in U.S. Pat. No. 6,431,518 B1 and U.S. Pat. No. 6,237,892 B1.